Imagine your next doctor's visit taking place in a sleek River North space where you also have the option for a high-intensity group workout and a cold-brew coffee.

Welcome to Shift, a concierge practice in River North run by Dr. Ari Levy, an internist and former Blackhawks team doctor who has an MBA from the University of Chicago. As concierge medicine—paying out-of-pocket in exchange for better access to a primary care doc—becomes increasingly commonplace among executives, Levy and others are capitalizing on the trend. Since launching Shift in March, he has built up the practice to about 200 early "patient-members," as he calls them, who can pay from about $3,000 for an annual primary care membership to $6,300 for doctor access plus gym membership and check-ins with fitness and nutrition coaches.

At Shift, doctor access isn't just your annual physical—it also means that Levy or his partner, Dr. Bruce Doblin, accompanies you to specialist appointments and has regular five-minute check-ins or text conversations. Levy says he'll cap the number of patients at about 1,500 to preserve one-on-one attention.

"Health is earned, not given," he says on a recent morning in Shift's gleaming subway-tiled kitchen, his crisp pitch blending a physician's reassuring authority with a CEO's results-driven mindset. "We're creating an accountability structure that changes the conversation about how people think about health in daily life."

All new members undergo an eight-hour executive physical and in-depth conversation with Levy about their health history, their work stresses, family dynamics and everything in between. They then get a report of their lab work ("metrics" in Shift parlance) and a detailed plan that establishes goals and steps to, say, reduce body fat and cholesterol. If they need a specialist, no problem—Shift uses Epic, the same electronic medical records system used by many doctors' offices, so patient records are easily transferable—although anything outside of Shift's doors isn't covered by the membership.

Could this be the future of medicine?

Justin Ishbia thinks so. "We're still in the first inning of the concierge medicine wave," says the founding partner of Shore Capital, a Chicago-based health care private-equity shop. His firm owns Specialdocs, a national concierge practice with close to a dozen locations in Chicago and the suburbs.

The number of primary care doctors involved in "retainer medicine" has grown between 50 and 55 percent each year from 2010 to 2015, according to Kevin Grabenstatter, a San Francisco-based managing partner at L.E.K. Consulting. Nationwide, between 7,500 and 8,000 doctors today work for a concierge practice. It's a big spike but represents only a tiny fraction of the medical market and about 1 percent of practicing primary care physicians.

Grabenstatter, who pegs Chicago at ninth among the 10 cities with the busiest concierge medicine business, says he's bullish on the industry from both a supply and demand perspective. "High-deductible health plans are a tailwind for this market," as people get used to ponying up their own money for health care, he says. "Word is getting out that there's a way around the headaches associated with traditional health care."

On the physician side, he says, "you can't throw a rock without hitting a primary care doctor who's fed up with the size of their (patient load), declining reimbursements and the administrative burden" associated with new electronic medical records rules.

Dr. Steven Gallo is one of those doctors. A former family physician affiliated with Northwestern Medicine, he was initially skeptical when he got a phone call from Peter Hoedemaker, the Seattle-based CEO of MD2, which has practices in 10 cities including New York, Boston, San Francisco and Silicon Valley epicenter Menlo Park. Billing itself as the founder of concierge medicine, the 21-year-old company charges $25,000 annually per family and restricts each doctor to 50 families.

"I would never have done this on my own, but Peter emailed me and pitched it as, 'You can have a different life,' " Gallo says. At the time, he was seeing a patient every 10 minutes, but not much of his four children, one of whom has serious medical problems. After peppering Hoedemaker with 200 questions scribbled on a legal pad, Gallo joined MD2 in 2008. He says the decision has been a great one.

Instead of seeing 40 people or more each day, he sees four or five and spends at least an hour with each at his North Michigan Avenue office. He's still busy—sitting in on oncologist appointments, for example—but he also has time to exercise, volunteer at a free clinic once a week and teach medical students.

"Back when I made the choice, some people looked at me squinty-eyed—'Why are you doing this?' " he says. "But now the novelty has worn off. Half of my friends have started doing some sort of concierge practice or are talking about it." Today, Gallo and his partner, Dr. Joe Hennessy, who is affiliated with Rush University Medical Center, have an ever-growing waitlist.

CEO Hoedemaker says MD2 is growing rapidly, even as eyebrows arch over the ethics associated with providing better care to those who can pay.

"We agree—health care shouldn't just be for the rich," he says. "Unfortunately, someone else changed the system, and it wasn't us. It was the politicians, the insurance companies. I get the ethical component. But for some doctors who have worked in the traditional system for years and want to treat people at a certain depth—well, they've earned it. And we're sparking innovation that we hope leads to larger change."